Introduction to the ControlLogix Reset Dominant (RESD) Instruction The ControlLogix Reset Dominant (RESD) will set an output only if the SET bit was the last bit to go true. For example, if both SET, and RESET are true, the RESET will win, and the output will be off. This is Read More »
Introduction to the ControlLogix D Flip Flop (DFF) The ControlLogix D Flip Flop (DFF) Instruction simply samples the input. If the input is true when the clock signal goes high, the Q output comes on, and stays on. On the other hand, if the input is low when we clock Read More »
Introduction to ControlLogix Up/Dn Accumulator (UPDN) The ControlLogix Up/Dn Accumulator (UPDN) instruction might seem a little confusing at first. It’s operation is very simple though. For example, we have two flow rates of a tank. The first rate is flow in. Likewise, the second rate is flow out. We can Read More »
Introduction to the ControlLogix Enhanced Select (ESEL) Instruction All things considered, the ControlLogix Enhanced Select (ESEL) simply selects between tags to choose the best suited value to use in logic. For example, if you have two process variables for a PID, you might select the lowest, highest, or average of Read More »
ControlLogix Moving Average (MAVE) The ControlLogix Moving Average (MAVE) allows you to smooth out a noisy process variable. In other words, if your signal is bouncing around, the MAVE instruction will smooth it out. For example, let’s consider a flow rate. Because of disturbances in the flow of a liquid, Read More »
